The invention relates to surface functionalized diamonds and diamond crystals. The surface functionalized diamonds and diamond crystals exhibit improved bond strengths with coatings and matrix materials. In particular, the invention relates to methods for producing surface functionalized diamonds and diamond crystals that exhibit enhanced bond retention in abrasive products.
Saw blades, grinding wheels, drill bits, and similar abrasive products (hereinafter "abrasive products"), which are used in machining and grinding of hard materials, often comprise diamonds and diamond crystals (hereinafter "diamond crystals"). The diamond crystals are placed in a matrix and are bonded to a tool or device, such as a grinding wheel and a saw blade segment, to form an abrasive product. The diamond crystals comprise naturally occurring diamonds or manufactured (synthetic) diamonds. The manufactured diamonds comprise any synthetic diamond, such as, but not limited to, diamonds manufactured by a high-pressure, high-temperature (HPHT) processes and chemical vapor deposition (CVD) processes. The bond of the matrix and diamond crystals is referred to as an abrasive bond. The abrasive bond is formed by a mechanical or chemical processes, and may comprise metallic, vitreous, or resin bonds.
Some diamond crystals, which are used in abrasive products, comprise a coating layer of metal for enhancing an adhesive bond strength. The coatings may comprise metal films, such as titanium, nickel, copper, and chromium films. The metal coatings are deposited on diamond crystal surfaces by an appropriate process, such as, but not limited to, evaporation and sputter deposition in vacuum. The metal coatings form bonds with the surfaces of the diamond crystals.
Abrasive products often fail during use. The failure can be caused by separation of the diamond crystal from the matrix or de-bonding of the metal coating from the diamond crystal. Improving a bond strength between the diamond crystal and the matrix metal and between the diamond crystal and the metal coating will lead to improved abrasive products tools, increased abrasive product life and value, and superior abrasive product performance.